I have 3 SATA drives, with grub in the MBR of hd0.
I have three OS installed, one in HD0,0 HD0,9 the other in HD1,0.
I have tried several different boot methods. The latest one is this:
Menu.lst of hd0,9/boot/grub;
timeout 10
color black/cyan yellow/cyan
gfxmenu (hd0,9)/boot/gfxmenu
default 0
title linux
kernel (hd0,9)/boot/vmlinuz BOOT_IMAGE=linux root=LABEL=root
splash=silent vga=788
initrd (hd0,9)/boot/initrd.img
title linux-nonfb
kernel (hd0,9)/boot/vmlinuz BOOT_IMAGE=linux-nonfb root=LABEL=root
linux-nonfb
initrd (hd0,9)/boot/initrd.img
title failsafe
kernel (hd0,9)/boot/vmlinuz BOOT_IMAGE=failsafe root=LABEL=root failsafe
initrd (hd0,9)/boot/initrd.img
title Mageia
configfile (hd1,0)/boot/grub/menu.lst
menu.lst of hd1,0/boot/grub is:
timeout 10
color black/cyan yellow/cyan
gfxmenu (hd1,0)/boot/gfxmenu
default 0
title linux
kernel (hd1,0)/boot/vmlinuz BOOT_IMAGE=linux root=LABEL=newroot
splash=silent vga=788
initrd (hd1,0)/boot/initrd.img
title windows
root (hd0,0)
makeactive
chainloader +1
My problem is whatever method I use, I cannot boot from hd1,0.
Error is partition doesn't exist.
Pressing return to continue and attempting to boot from hd0,9, produces
an error about number of cylinders being wrong ( don't remember exactly
). Only cure is a soft reboot.
If someone would point me in the right direction or let me know whatever
other info I need to supply, I'd be most grateful.
Jim

Hi Jim,

First remove any USB sticks or USB hard drives - I have issues here
booting sdb with a stick inserted - (buggy BIOS)

If it's not that then:-

Boot into Mandriva boot menu, hit ESC, ENTER then c and you should be at
a grub prompt.

At the prompt type "root (" without quotes and hit TAB not ENTER.
This should list the drives that grub can see (hd0) (hd1) etc.
So, question is, what can it see.
What it can see depends on what your BIOS tells it.
My recommendation for setting up Mageia would be:-

If you intend to make Mageia your main distro (good choice :) then make
sure that it's drive is drive 0 (first in BIOS) and is on channel 0 of
your SATA controller so it is assigned as sda by Mageia.

Once in Mageia you will be able to use MCC (Mageia Control Center) to
re-create the bootloader using the boot setup routine.
This should find your other OS's I guess Windows and Mandriva and add
them to the menu - but this will depend on the BIOS.
If you still have the partition not found on hd1, try removing hd2
temporarly.